The present invention relates to a method and catheter to be used in the creation of tricuspid regurgitation for the treatment of congestive heart failure.
Congestive Heart Failure (CHF) is a condition characterized by the inability of the heart to pump blood at a rate needed to maintain adequate blood flow throughout the body. CHF most commonly occurs as a result of ischemic heart disease, myocardial infarction, cardiomyopathy, or valvular disorders. In these conditions, the left ventricle (which pumps oxygenated blood to the body) can fail, while the right ventricle (which pumps deoxygenated blood to the lungs) continues to function normally. When this occurs, the pulmonary arterial pressures increase and fluid begins to exude from the pulmonary capillaries into the pulmonary interstitium and eventually into the alveoli, the tiny air sacs where gas exchange takes place. Fluid in the alveoli impedes gas exchange across the alveolar membranes, which then lowers the blood oxygenation. The resulting hypoxemia has a detrimental effect on the cardiac muscle, which requires large amounts of oxygenated blood to function normally, and results in an even more profound heart failure. This cycle, if left untreated, continues until the patient succumbs, in effect, drowning in his own pulmonary fluids.
Conventional therapies for CHF act by reducing pulmonary arterial pressures, and consist of drugs which either: (1) reduce overall blood volume, or "pre-load reducers" ( i.e., diuretics); (2) reduce systemic capillary resistance, or "after-load reducers" (i.e., vasodilators); or (3) enhance cardiac function, or "inotropic" agents (i.e., digitalis). These conventional therapies are usually very effective in the treatment of CHF, and their benefits often quite dramatic. Occasionally, however, a patient may develop CHF that is refractory to all conventional treatments. These patients are in danger of succumbing to the effects of hypoxemia unless some other treatment is begun which can break the heart failure--pulmonary edema cycle. For these patients, the instant invention offers an alternative therapy.
The concept for this catheter came from the knowledge that some patients with CHF who develop tricuspid regurgitation in the course of their disease may actually experience improvement in their pulmonary symptoms.
The tricuspid valve is a one-way valve located between the right atrium and right ventricle, and regulates blood flow between the two cavities. When the ventricles dilate during diastole, the tricuspid valve opens to allow deoxygenated blood to flow from the right atrium to the right ventricle. When the ventricles contract during systole, the tricuspid valve closes to prevent blood from refluxing back into the right atrium. Simultaneously, the pulmonary valve opens, and the deoxygenated blood is ejected from the right ventricle into the pulmonary arteries enroute to the lungs.
Tricuspid regurgitation, a condition whereby a faulty valve allows blood to reflux backward through the valve into the right atrium, can sometimes occur naturally in the course of congestive heart failure. It has been found that some patients who develop tricuspid regurgitation during the course of CHF actually experience improvements in their pulmonary symptoms. One might then ask whether patients with CHF who are refractory to conventional treatments might benefit from the creation of a reversible and controllable tricuspid regurgitation. The instant invention discloses catheter apparatus and a method for controllably inducing tricuspid regurgitation in those patients.
There are many devices disclosed in the prior art which have been developed for use on patients with cardiac problems. U.S. Pat. No. 4,861,330 (Voss) discloses a cardiac assist device comprised of an inflatable balloon that is inserted into a collapsed ventricle of the heart. The balloon is inserted into the ventricle through a coronary valve by means of a catheter, radiopaque dye and skilled surgery. The tip of the balloon houses a needle that holds the balloon in place. Inflation and deflation of the balloon is controlled from outside the body and is synchronized with the beating of the cavity housing the device. As a result, the cavity is assisted in expanding, contracting, and in pumping blood. The assistance is two fold in both the radial pressure the balloon puts on the ventricle walls and the added mass of the balloon within the ventricle increasing the internal pressure and therefore outflow of blood.
U.S. Pat. No. 5,034,001 (Garrison et al.) discloses a device and method for repairing a damaged blood vessel. The device comprises a catheter with a mesh-like shell about a center bar that is radially expandable and contractible. The mesh is hollow so as to allow the free flow of blood within it. The device is navigated into the damaged blood vessel by conventional surgical means. Once within the damaged area, the mesh, through externally controlled means, is radially expanded to the diameter of the damaged vessel to absorb the vessel pressure. The spacing of the mesh fibers are such that any flaps (loose hanging pieces of the vessel wall that may fall down into the vessel cavity thus blocking the flow of blood) are held in place and allowed to heal. This device is generally, although not limited to use within arteries.
U.S. Pat. No. 4,781,682 (Patel) discloses a device and method for inserting a catheter into an artery or the like. The device includes a guiding hollow catheter housing a dilating catheter therein. The guiding catheter deposits the dilating catheter into the narrowing of an artery for the performance of coronary angiography and angioplasty. The device further includes outer flaps mounted on an outer tube which when extended, from controls outside the body, serve as a mount to secure in place the dilating catheter.
U.S. Pat. No. 4,834,724 (Geiss et al.) discloses a device for aspirating fluids from a body cavity or hollow organ such as the stomach. The device comprises two lumens, one acting as a sump for the other. The device has a helical end for aligning the intake end with the lining of the stomach. The end also has ports facing in all directions so as to prevent the drawing in of stomach lining thus preventing the creation of an ulcer and internal piercing.
U.S. Pat. No. 3,828,767 (Spiroff) discloses a catheter with a tip comprising axial spaced holes of different diameters. The hole arrangement provides for the controlled ejection of fluid from a catheter end without the uncontrolled whipping associated with pressure build up within the catheter end. The result includes an end to the uncontrolled whipping about of the catheter tip and damage caused thereby.
U.S. Pat. No. 5,076,285 (Hess et al.) discloses a medical electrode lead comprising a helical extension from the distal end for screwing into heart tissue thereby mounting the device within the heart.
U.S. Pat. No. 4,952,215 (Ouriel et al.) discloses a volvultome for opening the valves of the veins in the event of failure. The disruption occurs as a result of disrupting heads mounted on the end of a rigid support. The device is inserted through an incision and is lead along the vein to the problem valve.
U.S. Pat. Des. Nos. 33,246 (Pumphrey) and 59,952 (Bruen) disclose designs for syringe nozzles. U.S. Pat. Des. No. 33,456 (Harris) discloses a design for a catheter.
U.S. Pat. No. 5,106,381 (Chikama) discloses a bending device for use with an endoscope, catheter or the like, comprised of a cylindrical frame housing therein, annular portions, and openings within said annular portions, divided by resilient thin plates for the flow of blood therein. The device further comprises wires for bending the frame and thin plates.
U.S. Pat. No. 3,592,184 (Watkins) discloses a device and method for siphoning and replacing blood. The device comprises a catheter inserted into the aorta, a membrane expanded radially to set the catheter centrally within the hollow of the aorta, two end placed ports for the intake and outtake of blood and means to connect the catheter to a blood pump.
U.S. Pat. No. 5,041,084 (Devires et al.) discloses a single stage catheter inserted into the right atrium through the superior vena cava. The catheter is used during open heart surgery to bypass the flow of oxygen poor blood away from the heart and into a life support unit. The catheter further includes several openings positioned to fall within the right atrium as well as a spiral lead flute for insertion into the inferior vena cava.
U.S. Pat. Des. No. 196,998 (Glassman) discloses a design patent for a common bile duct probe. In addition, Glassman, in U.S. Pat. No. 4,299,225, discloses a device for removal of gall stones from the common bile duct. The device comprises a catching basket securely fastened between two catheter ends that allow the device to be easily inserted through an incision and freely moved along the bile duct. During movement, the dislodging basket can be contracted and expanded as needed.
U.S. Pat. No. 4,927,426 (Dretler) discloses a catheter device for capturing, disintegrating and then discharging the remains of kidney stones and the like. A capturing head, housed within the catheter, is extended to capture a kidney stone, and then is retracted into the catheter with the stone lodged therein. A laser is used to disintegrate the stone and the capturing head is then extended outside the catheter body wherein the disintegrated remains of the kidney stone are released.
However, none of the many devices disclosed in the prior art which have been developed for use on patients with cardiac problems address the problem of creating a tricuspid regurgitation.